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Scintillation Arc from FRB 20220912A

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 134-142页

作者： Zi-wei Wu Robert AMain wei-wei zhu Bing Zhang Peng Jiang Jia-Rui Niu Jin-Lin Han Di Li Ke-Jia Lee Dong-Zi Li Yuan-Pei Yang Fa-Yin Wang Rui Luo Pei Wang Chen-Hui Niu Heng Xu Bo-Jun Wang wei-Yang Wang Yong-Kun Zhang Yi Feng De-Jiang Zhou Yong-Hua Xu Can-Min Deng Yu-Hao zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Max-Planck-Institut für Radioastronomie Bonn 53121Germany Institute for Frontier in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Nevada Center for Astrophysics and Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy University of Chinese Academy of SciencesBeijing 100049China NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa Department of Astronomy Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Cahill Center for Astronomy and Astrophysics California Institute of TechnologyPasadena 91125USA South-Western Institute For Astronomy Research Yunnan UniversityKunming 650504China School of Astronomy and Space Science Nanjing UniversityNanjing 210093China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210023China CSIRO Space and Astronomy Epping 1710Australia Department of Astronomy School of Physics and Materials ScienceGuangzhou UniversityGuangzhou 510006China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China

We present the interstellar scintillation analysis of fast radio burst(FRB)20220912A during its extremely active episode in 2022using data from the Five-hundred-meter Aperture Spherical Radio Telescope(FAST).We detect a scintillation arc in the FRB’s secondary spectrum,which describes the power in terms of the scattered FRB signals’time delay and Doppler shift.The arc indicates that the scintillation is caused by a highly localized region.Our analysis favors a Milky Way origin of the ionized interstellar medium(IISM)for the localized scattering medium but cannot rule out a host galaxy origin.We present our method for detecting the scintillation arc,which can be applied generally to sources with irregularly spaced bursts or pulses.These methods could help shed light on the complex interstellar environment surrounding the FRBs and in our Galaxy.

关键词： fast radio burst scintillation FRB 20220912A

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Cognitive dysfunction in schizophrenia patients caused by downregulation of γ-aminobutyric acid receptor subunits

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World Journal of Psychiatry 2024年第6期14卷 784-793页

作者： Xi Chen Ya-Nan Zhou Xiao-Zi Lu Ren-Jiao Li Yi-Fan Xiong Xia Sheng wei-wei zhu Department of Child and Adolescent Psychiatric Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina Department of Psychiatry Qingdao Mental Health CenterQingdao 266034Shandong ProvinceChina Department of Psychiatry Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina Department of Sleep Disorders and Neurosis Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina

BACKGROUND The expression pattern of gamma aminobutyric acid(GABA)receptor subunits are commonly altered in patients with schizophrenia,which may lead to nerve excitation/inhibition problems,affecting cognition,emotion,and behavior.AIM To explore GABA receptor expression and its relationship with schizophrenia and to provide insights into more effective treatments.METHODS This case-control study enrolled 126 patients with schizophrenia treated at our hospital and 126 healthy volunteers who underwent physical examinations at our hospital during the same period.The expression levels of the GABA receptor subunits were detected using 1H-magnetic resonance spectroscopy.The recognized cognitive battery tool,the MATRICS Consensus Cognitive Battery,was used to evaluate the scores for various dimensions of cognitive function.The correlation between GABA receptor subunit downregulation and schizophrenia was also analyzed.RESULTS Significant differences in GABA receptor subunit levels were found between the case and control groups(P0.05).CONCLUSION Downregulation of the GABA receptor subunits is positively correlated with schizophrenia.In other words,when GABA receptor subunits are downregulated in patients,cognitive impairment becomes more severe.

关键词： Cognitive function Schizophrenia Downregulation Gamma-aminobutyric acid receptor subunits Correlation

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A short review on the role of alloying elements in duplex stainless steels

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Tungsten 2023年第4期5卷 419-439页

作者： Ying Han Zheng-Hong Liu Chun-Bo Wu Yu Zhao Guo-Qing Zu wei-wei zhu Xu Ran Key Laboratory of Advanced Structural Materials Ministry of EducationChangchun University of TechnologyChangchun130012China School of Materials Science and Engineering Changchun University of TechnologyChangchun130012China Jilin Province Key Laboratory of Advanced Materials Processing and Application for Rail Transit Changchun University of TechnologyChangchun130012China

Duplex stainless steels consisting of ferrite and austenite are widely used due to their excellent mechanical properties and corrosion resistance.Compared with ferritic stainless steels,duplex stainless steels have better plasticity,toughness,and welding performance.They also possess higher strength and better resistance to stress,pitting,and crevice corrosion than austenitic stainless steels.In addition to the above-mentioned properties,there are cost-saving advantages in duplex stainless steels due to their lower nickel content.Today,the types of duplex stainless steel are mainly divided into four categories:lean duplex stainless steel,standard duplex stainless steel,super duplex stainless steel,and hyper duplex stainless steel.Alloying design of duplex stainless steel is an important strategy to achieve high performance.In the last two decades,significant progress has been made in both theoretical calculations and experiments.By adjusting alloying elements such as chromium,nickel,molybdenum,nitrogen,copper,tungsten and rare earth,etc.,the mechanical properties and/or corrosion resistance of the duplex stainless steels can be further improved.Summarizing the comprehensive progress of alloying design of duplex stainless steel is of great significance in providing a data basis for establishing the corresponding relationship between chemical compositions and properties.Therefore,this paper reveals the specific roles of alloying elements in the duplex stainless steels and provides a reference for alloying design with different performance requirements.

关键词： Duplex stainless steel Chemical component Alloying Mechanical property Corrosion resistance

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Atomic layer deposition of zinc oxide onto 3D porous iron scaffolds for bone repair:in vitro degradation,antibacterial activity and cytocompatibility evaluation

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Rare Metals 2022年第2期41卷 546-558页

作者： Yu-Lei Li Jin He Hai-Xia Ye Can-Can Zhao wei-wei zhu Xiong Lu Fu-Zeng Ren Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Institute of Applied Physics and Materials Engineering Faculty of Science and TechnologyUniversity of MacaoMacao 999078China Key Lab of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

3D porous iron(Fe)scaffolds with interconnected open pores are promising candidates for bone repair.However,the bare 3D porous Fe scaffolds lack of antibacterial activity and the ability for cell adhesion.Herein,atomic layer deposition technique was used to deposit nanometer-thick zinc oxide(ZnO)layer onto the skeleton of 3D porous Fe scaffolds with interconnected open pores.The effect of ZnO thin film on the in vitro degradation behavior,antibacterial activity and cytocompatibility of 3D porous Fe scaffolds was systematically evaluated.The results showed that a dense ZnO thin film with a thickness of 76 nm was uniformly deposited on the skeleton of the porous Fe scaffolds.The thickness of ZnO thin film could be easily controlled by the deposition cycles.The deposited ZnO thin film significantly reduced the degradation rate of porous Fe scaffolds and the fabricated ZnO coated porous Fe scaffolds demonstrated strong antibacterial ability against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus,while did not significantly affect cytocompatibility and could also promote cell adhesion.

关键词： Atomic layer deposition Porous iron scaffolds ZnO Antibacterial activity

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Cesarean Section Rate in Singleton Primiparae and Related Factors in Beijing, China

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Chinese Medical Journal 2017年第20期130卷 2395-2401页

作者： Geng Song Yu-Mei wei wei-wei zhu Hui-Xia Yang Department of Obstetrics and Gynecology Peking University First Hospital Beijing 10034 China Exchange and Cooperation Division National Institute of Hospital Administration Beijing 100191 China

Background： The cesarean section rate （CSR） bas been a main concern worldwide. The present study aimed to investigate the CSR in Beijing, China, and to analyze the related lactors of CS delivery. Methods： An observational study was conducted in 15 medical centers in Beijing using a systemic cluster sampling naethod. In total, 15, 194 pregnancies were enrolled in the study between ,lune 20, 2013 and November 30, 2013. Independent t-tests and Pearson＇s Chi-square test were nsed to examine differences between two groups, and related factors of the CSR were examined by multivariable logistic regression. Results： The CSR was 41.9% （4471/10,671） in singleton primiparae. Women who were more than 35 years old had a 7.4-fold increased risk of CS delivery compared with women 〈25 years old （odd ratio [OR] 7.388, 95% confidence interval [Cl] = 5.561-9.816, P 〈 0.001 ）. Prepregnancy obese women had a 2-1bid increased risk of CS delivery compared with prepregnancy normal weight women （OR = 2.058. 95% CI = 1.640-2.584, P〈 0.001 ）. The excessive weight gain group had a 1.4-fold increased risk of CS delivery compared with the adequate weight gain group （OR 1.422, 95% CI = 1.289 1.568, P〈 0.001 ）. Gestational diabetes mellitus （GDM） women and DM women had an increased risk of CS delivery （ 1.2- and 1.7-fold, respectively） compared with normal blood glucose women. Women who were born in rural areas had a lower risk of CS delivery than did those who were born in urban areas （OR 0.696, 95% CI = 0.625-0.775, P 〈 0.001 ）. The risk of CS delivery gradually increased with a decreasing education level. Neonates weighing 3000-3499 g had the lowest CSR （36.2%）. Neonates weighing 〈2500 g had a 2-fold increased risk of CS delivery compared with neonates weighing 3000 3499 g （OR - 2.020, 95% CI=1.537 2.656, P 〈 0.001 ）. Neonates weighing ≥4500 g had an 8.3-fold increased risk of CS delivery compared with neonates weighing 3000-3499 g （OR = 8.313.95% CI= 4.436-15.579, P 〈 0.001）. Conclusions： Maternal age, prepregnancy body mass index, geslatio

关键词： Blood Glucose Levels Cesarean Section Rate Gestational weight Gain： Prepregnancy Body Mass Index Related Factors

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Precipitation Behavior of FeTiP in Ti-added Interstitial Free High Strength Steels

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Journal of Iron and Steel Research(International) 2016年第7期23卷 692-698页

作者： Juan JIA wei-wei zhu Xin-li SONG Ze-xi YUAN The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Department of Materials Science and Engineering South University of Science and Technology of China

The precipitation behavior of FeTiP in interstitial free high strength（IFHS）steels has been studied by using a transmission electron microscope（TEM）.The results show that the TiC particles,appearing at earlier stage,are more stable than the FeTiP ones during recrystallization annealing at the two given temperatures（810℃ and 840℃）.Therefore,the FeTiP particles can only be observed in the steels with sufficient amount of Ti.There is a critical forming time for the FeTiP,which is between 90-120 sat 810 ℃ and 60-90 sat 840 ℃.The precipitation of FeTiP involves two steps,i.***.the formation of FeTi precursors and the diffusion of P.The former step determines the reliance of Ti content for the precipitation of FeTiP,whereas the latter step leads to the difference in the critical annealing time.

关键词： interstitial free high strength steel FeTiP precipitation critical annealing formation mechanism

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High Prevalence of Gestational Diabetes Mellitus in Beijing： Effect of Maternal Birth weight and Other Risk Factors

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Chinese Medical Journal 2017年第9期130卷 1019-1025页

作者： wei-wei zhu Hui-Xia Yang Chen Wang Ri-Na Su Hui Feng Anil Kapur Department of Obstetrics and Gynecology Peking University First Hospital Beijing 100034 China Exchange and Cooperation Division National Institute of Hospital Administration Beijing 100191 China World Diabetes Foundation Gentofte 2820 Denmark

Background： Gestational diabetes mellitus （GDM） is associated with both short- and long-term adverse health consequences for both the mother and her offspring. The aim was to study the prevalence and risk factors for GDM in Beijing. Methods： The study population consisted of 15,194 pregnant women attending prenatal care in 15 hospitals in Beijing, who delivered between June 20, 2013, and November 30, 2013, after 28 weeks of gestation. The participants were selected by cluster sampling from the 15 hospitals identified through random systematic sampling based on the number of deliveries in 2012. A questionnaire was designed to collect information. Results： A total of 2987 （19.7%） women were diagnosed with GDM and 208 （1.4%） had diabetes in pregnancy （DIP）, Age （OR： 1.053, 95% CI： 1.033-1.074, P 〈 0.01）, family history of diabetes mellitus （OR： 1.481, 95% CI：1.254 1.748, P 〈 0.01）, prepregnancy body mass index （BMI）（OR： 1.481, 95% CI：1.254 1.748, P 〈 0.01）, BMI gain before 24 weeks （OR： 1.126, 95% CI： 1.075-1.800, P 〈 0.01 ）, maternal birth weight （P 〈 0.01）, and fasting plasma glucose at the first prenatal visit （P 〈 0.01） were identified as risk factors for GDM. In women with birth weight 〈3000 g, GDM rate was significantly higher. Conclusions： One out of every five pregnant women in Beijing either had GDM or DIP and this constitutes a huge health burden for health services. Prepregnancy BMI and weight gain before 24^th week are important modifiable risk factors for GDM. Ensuring birth weight above 3000 g may help reduce risk for future GDM among female offsprings.

关键词： Gestational Diabetes Mellitus Maternal Low Birth weight Risk Factors

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Relationship between Oral Glucose Tolerance Test Characteristics and Adverse Pregnancy Outcomes among Women with Gestational Diabetes Mellitus

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Chinese Medical Journal 2017年第9期130卷 1012-1018页

作者： Hui Feng wei-wei zhu Hui-Xia Yang Yu-Mei wei Chen Wang Ri-Na Su Moshe Hod Eran Hadar Department of Obstetrics and Gynecology Peking University First Hospital Beijing 100034 China Exchange and Cooperation Division National Institute of Hospital Administration Beijing 100191 China Helen Schneider Hospital for Women Rabin Medical Center Sackler Faculty of Medicine TeI-Aviv University Petah-Tiqva TeI-Aviv 6997801 Israel

Background： Hyperglycemia is associated with adverse pregnancy outcomes. However, the relationships between them remain ambiguous. This study aimed to analyze the effect of different oral glucose tolerance test （OGTT） results on adverse perinatal outcomes. Methods： This retrospective cohort study included data from 15 hospitals in Beijing from June 20, 2013 to November 30, 2013. Women with gestational diabetes mellitus （GDM） were categorized according to the number and distribution of abnormal OGTT values, and the characteristics of adverse pregnancy outcomes were evaluated. Chi-square test and logistic regression analysis were used to determine the associations. Results： in total, 14,741 pregnant women were included in the study population, 2927 （19.86%） of whom had G DM. As the number of hyperglycemic values in the OGTT increased, the risk of cesarean delivery, preterm births, large-for-gestational age （LGA）, macrosomia, and neonatal complications significantly increased. Fasting hyperglycemia bad clear associations with macrosomia （odds ratios [ORs]：1.84, 95% confidence intervals [CIs]： 1.39-2.42, P 〈 0.001）, L（SA （OR： 1.70, 95% CI： 1.29-2.25. P 〈 0.001）, and cesarean delivery （OR： 1.33, 95% CI： 1.15-1.55, P 〈 0.001）. The associations were stronger as tasting glucose increased. GDM diagnosed by hyperglycemia at OGTT-2 h was more likely to lead to preterm birth （OR： 1.50, 95% Cl： 1. 11-2.03, P 〈 0.01）. Conclusions： Various characteristics of OGTTs are associated with different adverse outcomes. A careful reconsideration ofGDM wiih hierarchical and individualized management according to OGTT characteristics is needed.

关键词： Cesarean Delivery Gestational Diabetes Mellitus Glucose Tolerance Test Large-for-gestational Age Macrosomia Pregnancy Outcomes Preterm Births

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Revisiting pulsar velocities using Gaia Data Release 2

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Research in Astronomy and Astrophysics 2021年第6期21卷 294-300页

作者： Meng Yang Shi Dai Di Li Chao-wei Tsai wei-wei zhu Jie Zhang China West Normal University Nanchong 637000China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Science Western Sydney UniversityLocked Bag 1797Penrith NSW 2751Australia CSIRO Astronomy and Space Science Australia Telescope National FacilityPO Box 76EppingNSW 1710Australia University of Chinese Academy of Sciences Beijing 100049China NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa Qilu Normal University Zhangqiu 250200China

Precise measurements of neutron star(NS)velocities provide critical clues in regard to the supernova physics and evolution of binary systems.Based on Gaia Data Release 2(DR2),we selected a sample of 24 young(<3 Myr)pulsars with precise parallax measurements and measured the velocity of their local standard of rest(LSR)and the velocity dispersion among their respective local stellar groups.The median velocity difference between thus calculated LSRs and the Galactic rotation model is~7.6 km s^(-1),small compared to the typical velocity dispersion of~27.5 km s^(-1).For pulsars off the Galactic plane,such differences grow significantly to as large as~40 km s^(-1).More importantly,the velocity dispersion of stars in the local group of low-velocity pulsars can be comparable to their transverse velocities,suggesting that the intrinsic velocities of NS progenitors should be taken into account when we consider their natal kicks and binary evolution.We also examined the double NS system J0737-3039 A/B,and measured its transverse velocity to be 26-13+18 km s^(-1)assuming nearby Gaia sources are representative of their birth environment.This work demonstrated the feasibility and importance of using Gaia data to study the velocity of individual systems and velocity distribution of NSs.

关键词： (stars:) pulsars:general

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FAST Observations of an Extremely Active Episode of FRB 20201124A.Ⅱ.Energy Distribution

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Research in Astronomy and Astrophysics 2022年第12期22卷 70-80页

作者： Yong-Kun Zhang Pei Wang Yi Feng Bing Zhang Di Li Chao-wei Tsai Chen-Hui Niu Rui Luo Ju-Mei Yao wei-wei zhu Jin-Lin Han Ke-Jia Lee De-Jiang Zhou Jia-Rui Niu Jin-Chen Jiang wei-Yang Wang Chun-Feng Zhang Heng Xu Bo-Jun Wang Jiang-wei Xu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA Nevada Center for Astrophysics University of NevadaLas VegasNV 89154USA NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa CSIRO Space and Astronomy PO Box 76EppingNSW 1710Australia Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Department of Astronomy Peking UniversityBeijing 100871China

We report the properties of more than 800 bursts detected from the repeating fast radio burst(FRB)source FRB20201124A with the Five-hundred-meter Aperture Spherical radio Telescope(FAST)during an extremely active episode on UTC 2021 September 25–28 in a series of four papers.In this second paper of the series,we study the energy distribution of 881 bursts(defined as significant signals separated by dips down to the noise level)detected in the first four days of our 19 hr observational campaign spanning 17 days.The event rate initially increased exponentially but the source activity stopped within 24 hr after the 4th day.The detection of 542 bursts in one hour during the fourth day marked the highest event rate detected from one single FRB source so far.The bursts have complex structures in the time-frequency space.We find a double-peak distribution of the waiting time,which can be modeled with two log-normal functions peaking at 51.22 ms and 10.05 s,respectively.Compared with the emission from a previous active episode of the source detected with FAST,the second distribution peak time is smaller,suggesting that this peak is defined by the activity level of the source.We calculate the isotropic energy of the bursts using both a partial bandwidth and a full bandwidth and find that the energy distribution is not significantly changed.We find that an exponentially connected broken-power law function can fit the cumulative burst energy distribution well,with the lower and higher-energy indices being-1.22±0.01 and-4.27±0.23,respectively.Assuming a radio radiative efficiency ofη_(r)=10^(-4),the total isotropic energy of the bursts released during the four days when the source was active is already 3.9×10^(46)erg,exceeding~23%of the available magnetar dipolar magnetic energy.This challenges the magnetar models which invoke an inefficient radio emission(e.g.,synchrotron maser models).

关键词： (stars:)pulsars:general stars:individual(FRB 20201124A) methods:data analysis

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